Flowering Buds of Globular Proteins: Transpiring Simplicity of Protein Organization

Structural and functional complexity of proteins is dramatically reduced to a simple linear picture when the laws of polymer physics are considered. A basic unit of the protein structure is a nearly standard closed loop of 25–35 amino acid residues, and every globular protein is built of consecutively connected closed loops. The physical necessity of the closed loops had been apparently imposed on the early stages of protein evolution. Indeed, the most frequent prototype sequence motifs in prokaryotic proteins have the same sequence size, and their high match representatives are found as closed loops in crystallized proteins. Thus, the linear organization of the closed loop elements is a quintessence of protein evolution, structure and folding

Pattern-reversal visual evoked potential abnormalities in patients with defined multiple sclerosis

INTRODUCTION: Multiple sclerosis is an idiopathic demyelinating disease that may affect the optic nerve leading to acute unilateral visual loss, which could be observed by means of evoked visual potential (VEP). This exam is much valued for studying prechiasmatic visual paths in multiple sclerosis. PURPOSE: To analyze the findings of pattern reversal VEP in patients with prior diagnosis of multiple sclerosis and to compare them to visual acuity. METHODS: Twenty-four patients with a definite diagnosis of multiple sclerosis were submitted to pattern reversal VEP from October 2001 to March 2007. RESULTS: In P100 component response, at 15' and 1º stimuli, 19 eyes presented latency response up to 115 ms in both stimuli, which coincided in 6 eyes with latency response between 116 and 135 ms; 11 eyes had a latency response higher than 135 ms, and four eyes did not respond to stimuli. Correlating visual acuity with P100 latency for 15', in Pearson r correlation, r=0.85 with p=0.000000123, and for 1º, r = 0.87 with p=0.0000000338. CONCLUSION: Approximately 60.4% of patients presented abnormalities. However, the correlation between the P100 latency (15' and 1º) and visual acuity was statistically significant; therefore the better the visual acuity, the better the response to stimuli of the pattern-reversal VEP.INTRODUÇÃO: Esclerose múltipla é uma doença desmielinizante idiopática, podendo acometer o nervo óptico com perda visual unilateral aguda que pode ser observada através do potencial visual evocado (PVE), definindo tal exame como de grande validade para o estudo pré-quiasmático das vias visuais na esclerose múltipla. OBJETIVO: Analisar os achados dos potenciais visuais evocados por reversão de padrões em pacientes com diagnóstico prévio de esclerose múltipla e sua comparação com a acuidade visual. MÉTODOS: Vinte e quatro pacientes com diagnóstico definido de esclerose múltipla foram submetidos ao PVE por reversão de padrões no período de outubro de 2001 a março de 2007. RESULTADOS: Na resposta do componente P100, nos estímulos de 15' e 1º, se observou que 19 olhos apresentaram resposta de latência até 115 ms em ambas as estimulações, coincidindo também em 6 olhos que apresentaram resposta de latência entre 116 a 135 ms, em 11 olhos que apresentaram resposta de latências superiores a 135 ms, e em 4 olhos que não apresentaram respostas às estimulações. Correlacionando a acuidade visual com a latência de P100 para 15', obtemos na correlação de Pearson r= 0,85 com p= 0,000000123, e para 1º, r= 0,87 com p= 0,0000000338. CONCLUSÃO: Aproximadamente 60,4% dos pacientes apresentaram anormalidades no PVE por padrões reversos. Contudo, a correlação entre a latência de P100 (15' e 1º) e a acuidade visual foi estatisticamente significativa, assim sendo, quanto melhor a acuidade visual, melhor será sua resposta aos estímulos do PVE por reversão de padrões.Universidade de Santo AmaroUniversidade Federal de São Paulo (UNIFESP) Departamento de OftalmologiaUNIFESPUNIFESP, Depto. de OftalmologiaUNIFESPSciEL

Optical coherence tomography aspects of Stargardt's disease: case report

The term fundus flavimaculatus (Stargardt disease) describes a group of inherited macular dystrophies characterized by multiple yellow to yellow-white flecks at the level of the retinal pigment epithelium. The authors describe findings in the patient with Stargardt's disease using optical coherence tomography (OCT), and suggest the examination to be valid as subsidiary method in the study of the characteristics of the retina in Stargardt's disease patients, but studies involving a series of patients should be able to show the most frequent findings in these cases.O termo fundus flavimaculatus (doença de Stargardt) descreve um grupo de distrofias maculares hereditárias caracterizadas por múltiplos flecks amarelados em nível do epitélio pigmentar da retina. Os autores descrevem os achados de tomografia de coerência óptica (OCT) em paciente portador de doença de Stargardt e sugerem que a OCT tem validade como exame subsidiário no estudo das características da retina de pacientes portadores da doença de Stargardt, embora estudos envolvendo maior número de pacientes sejam indicados para permitir traçar-se o perfil das alterações mais comuns nestes casos.Universidade Federal de São Paulo (UNIFESP) Departamento de Oftalmologia Setor de Ultra-som OcularUNIFESP Departamento de Oftalmologia Setor de Ultra-som OcularUNIFESP Departamento de Oftalmologia Setor de Eletrofisiologia OcularUNIFESP Departamento de Oftalmologia Setor de RetinaUNIFESP, Depto. de Oftalmologia Setor de Ultra-som OcularUNIFESP, Depto. de Oftalmologia Setor de Ultra-som OcularUNIFESP, Depto. de Oftalmologia Setor de Eletrofisiologia OcularUNIFESP, Depto. de Oftalmologia Setor de RetinaSciEL

Neuromotor development and visual acuity in premature infants submitted to early visuo-motor stimulation

To investigate the effects of early visual stimulation on the development of tonus and posture control and of grating visual acuity of preterm infants, eight infants received visual stimulation that induced head motion during the first 6 months of life in weekly sessions. Their performance was compared with that of unstimulated preterm infants of same age (n = 6). Both groups were evaluated in the developmental scale of Gesell and had their grating visual acuity measured by swept visually evoked potentials (sweep-VEP). Visuomotor performance and adoption and maintenance of postures were significantly better for the stimulated group (p < .05) compared to the unstimulated group. There was no statistical difference between the two groups for the development of visual acuity. Visuo-motor and postural development improved with the early visuo-motor stimulation program. The lack of influence of this program in the development of visual acuity may be attributed to differences in the pathways involved in the processing of visual acuity of patterns and in the responses elicited by visuo-motor stimulation.Universidade de São PauloUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Electroretinography in dogs using a fiber electrode prototype

We compared two electroretinography (ERG) electrodes in dogs using ERG standards of the International Society for Clinical Electrophysiology of Vision (ISCEV). Ten healthy Yorkshire terrier dogs (mean age, 2.80 +/- 1.42 years; 6 females) weighing 5.20 +/- 1.56 kg were evaluated using an ERG system for veterinary use. Dark-and light-adapted ERG responses were recorded using an ERG-Jet electrode and a fiber electrode prototype. the examinations were performed during 2 visits, 3 weeks apart. Both electrodes (ERG-Jet or fiber prototype) were used on each animal and the first eye to be recorded (OD x OS) was selected randomly. Three weeks later the examination was repeated on the same animal switching the type of electrode to be used that day and the first eye to be examined. the magnitude and waveform quality obtained with the two electrode types were similar for all ERG responses. ERG amplitudes and implicit times obtained from dogs using the fiber electrode prototype were comparable to those obtained with the ERG-Jet electrode for rod, maximal rod-cone summed, cone, and 30-Hz flicker responses. the fiber electrode prototype is a low-cost device, available as an alternative instrument for clinical veterinary ERG recording for retinal function assessment.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Clin Vet Arca Noe, Atibaia, SP, BrazilUniv Fed Parana, Dept Vet Med, BR-80060000 Curitiba, Parana, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Oftalmol, São Paulo, BrazilWashington State Univ, Dept Vet Clin Sci, Pullman, WA 99164 USAUniversidade Federal de São Paulo, Escola Paulista Med, Dept Oftalmol, São Paulo, BrazilFAPESP: 04/02669-6FAPESP: 05/56459-5CNPq: 474251/2009-8Web of Scienc

Quantum computing with defects

Identifying and designing physical systems for use as qubits, the basic units of quantum information, are critical steps in the development of a quantum computer. Among the possibilities in the solid state, a defect in diamond known as the nitrogen-vacancy (NV-1) center stands out for its robustness - its quantum state can be initialized, manipulated, and measured with high fidelity at room temperature. Here we describe how to systematically identify other deep center defects with similar quantum-mechanical properties. We present a list of physical criteria that these centers and their hosts should meet and explain how these requirements can be used in conjunction with electronic structure theory to intelligently sort through candidate defect systems. To illustrate these points in detail, we compare electronic structure calculations of the NV-1 center in diamond with those of several deep centers in 4H silicon carbide (SiC). We then discuss the proposed criteria for similar defects in other tetrahedrally-coordinated semiconductors.Comment: 31 pages, 7 figures, 2 table

Promover os direitos das crianças - apostar na construção de melhores políticas públicas para a criança

Comunicação apresentada no 3º Encontro de Conhecimento e Cooperação, INA, Lisboa, 17 de setembro de 201